System and method for communicating data in a video system

Abstract

A system and method of controlling a video camera arranged to provide a video signal on a transmission medium including: transmitting command data on the video transmission medium to the camera, and receiving response data from the camera over the video transmission medium during a single vertical blanking period of the video signal, improving controllability of dome type cameras. Using an encoding format with data with bit widths narrower than those conventionally used in UTC protocols, increases the usable transmission medium length for the system by allowing for longer propagation delays without errors caused by interference. A method of downloading data to a camera by disabling the video signal, and a method of self-instantiating camera functions are also provided.

1 . A method of downloading data to a controllable video device configured to provide a video signal on a transmission medium, the method comprising:
 disabling at least an active portion of the video signal during said at least one vertical field of the video signal; and   transmitting the data in separate portions to the controllable video device over the transmission medium during a time when said active portion of said video signal is disabled, each of said separate portions being transmitted on an associated one of a plurality of horizontal lines in said vertical field, wherein each of said separate portions comprises a plurality of bits encoded in a bit period, a first logic value of each of said bits being represented by presence of a transition during said bit period and a second logic value of each of said bits being represented by absence of a transition during said bit period.   
     
     
         2 . A method according to  claim 1 , wherein said video signal is entirely disabled during said at least one vertical field. 
     
     
         3 . A method according to  claim 1 , wherein the data is transmitted to the controllable video device during the entirety of said at least one vertical field of said video signal. 
     
     
         4 . A video system comprising:
 a controllable video device configured to transmit a video signal on a transmission medium and to disable at least an active portion of the video signal during said at least one vertical field of the video signal; and   a command source configured to transmit data in separate portions to the controllable video device over the transmission medium during a time when said active portion of said video signal is disabled by said controllable video device, each of said separate portions being transmitted on an associated one of a plurality of horizontal lines in said vertical field, wherein each of said separate portions comprises a plurality of bits encoded in a bit period, a first logic value of each of said bits being represented by presence of a transition during said bit period and a second logic value of each of said bits being represented by absence of a transition during said bit period.   
     
     
         5 . A system according to  claim 4 , wherein said controllable video device is configured to entirely disable said video signal during said at least one vertical field of said video signal. 
     
     
         6 . A system according to  claim 4 , wherein said command source is configured to transmit the data to the controllable video device during the entirety of said at least one vertical field of said video signal. 
     
     
         7 . A method of controlling a controllable video device configured to provide a video signal on a transmission medium, the method comprising,
 transmitting a function command from a command source to said controllable video device over the transmission medium;   transmitting reply data to said command source, said reply data being in response to said function command and being configured to cause display of a plurality of available functions for said controllable video device;   transmitting a function start command to said controllable video device in response to said reply data, said function start command being configured to cause said controllable video device to perform at least one of said plurality of available functions.   
     
     
         8 . A method according to  claim 8 , wherein said function command is transmitted to said controllable video device in response to activation of at least one user interface control on said command source. 
     
     
         9 . A method according to  claim 8 , wherein said user interface control comprises a button on a user interface of said command source. 
     
     
         10 . A method according to  claim 7 , wherein said reply command is configured to cause the command source to display a numeric value associated with each of said available functions for said controllable video device. 
     
     
         11 . A method according to  claim 10 , wherein said function start command comprises data representing one of said numeric values associated with said at least one of said plurality of available functions. 
     
     
         12 . A method according to  claim 7 , wherein at least said function command and said reply data are transmitted during a single vertical blanking period of said video signal. 
     
     
         13 . A method according to  claim 12 , wherein said function command and said reply data are each transmitted in separate portions, each of said separate portions being transmitted on an associated one of a plurality of horizontal lines in said vertical blanking period. 
     
     
         14 . A method according to  claim 13 , wherein each of said separate portions comprises  16  bits. 
     
     
         15 . A method according to  claim 14 , wherein each of said 16 bits is encoded in a bit period, a first logic value of each of said bits being represented by presence of a transition during said bit period and a second logic value of each of said bits being represented by absence of a transition during said bit period. 
     
     
         16 . A video system comprising:
 a controllable video device configured to transmit a video signal on a transmission medium;   a command source including a user interface control for causing function command data to be transmitted to said controllable video device over the transmission medium, said controllable video device being configured to transmit reply data to said command source in response to said function command, said reply data being configured to cause display of a plurality of available functions for said controllable video device, wherein said reply data is configured to cause said command source to display a numeric value associated with each of said available functions for said controllable video device, and said command source is configured to transmit a function start command to said controllable video device in response to said reply data, said function start command being configured to cause said controllable video device to perform at least one of said plurality of available functions, and said function start command comprises data representing one of said numeric values associated with said at least one of said plurality of available functions.   
     
     
         17 . A system according to  claim 16  wherein said user interface control comprises a button on a user interface of said command source. 
     
     
         18 . A system according to  claim 16  wherein said command source and said controllable video device are configured to transmit said function command and said reply data, respectively, during a single vertical blanking period of said video signal. 
     
     
         19 . A system according to  claim 16 , wherein said command source and said controllable video device are configured to transmit said function command and said reply data in separate portions, each of said separate portions being transmitted on an associated one of a plurality of horizontal lines in said vertical blanking period. 
     
     
         20 . A system according to  claim 18 , wherein each of said separate portions comprises 16 bits, wherein each of said 16 bits is encoded in a bit period, a first logic value of each of said bits being represented by presence of a transition during said bit period and a second logic value of each of said bits being represented by absence of a transition during said bit period.